An important consideration in treating of liquids is to prevent contamination of untreated liquid with treated liquid. One suitable example exemplifying the need is a filtration devise wherein raw liquid enters a filtration unit, with filtered liquid exiting therefrom. It is required to prevent sealing breakthrough (at times this may be referred to as a ‘gasket/seal shortcut’, or as a ‘sealing element override’ of raw liquid towards the filtered (treated) liquid to prevent contamination thereof.
Another example is a liquid mixing system where a first liquid, say fresh water, is mixed with some chemical agent and the mixtures then egresses through an outlet of the liquid treating system. It is a requirement that the chemical agent does not flow downstream in direction of the first liquid, possibly contaminating the fresh water or even worse posing a hazardous situation.
Various solutions are generally proposed to reduce the likelihood of leak between upstream and downstream flow portions of a liquid treating system. Most common are sealing arrangements including various gaskets, O-rings, surface-to-surface contact sealing, etc.
However, it often occurs that such sealing arrangements are insufficient or fail, e.g. owing to high pressure fluids managing to overcome such sealing arrangements, or for example owing to the presence of dirt at the sealing vicinity (which may enter during assembly of the device or be carried thereto by the fluid), or owing to misplacing or pinching of a sealing member during assembly, or even owing to wear during the regular course of use which might take place both in the case of static devices and dynamic devices where one or more elements displace linearly and/or rotatably about a sealing element, where in the later case (dynamic devices) wear is generally increased.